Sprocket and roller combination for trussed tracks



H. Y. LAW

Dec. 4, 1951 SPROCKET AND ROLLER COMBINATION FOR TRUSSED TRACKS 3 Sheets-Sheet 1 Original Filed June 7, 1945 INVENTOR ATTORNEYS Dec. 4, 1951 H. Y. LAW 2,577,471

SPROCKET AND ROLLER COMBINATION FOR TRUSSED TRACKS Original Filed-June 7, 1945 3 Sheets-Sheet 2 INVENTOR j 2 3 BY .Harrg YLaw ATTORNEYS ec. 4, 1951 H. Y. LAW 2,577,471

SPROCKET AND ROLLER COMBINATION FOR TRUSSED TRACKS Original Filed June 7, 1943 3 Sheets-Sheet 5 INVENTOR Earry Y La w ATTORNEYS Patented Dec. 4, 1951 SPROCKETIAND'LROLLER COMBINATION ron'rRUSsED rnAoKs.

Hariy .Y. Law, Merced; Calif.

Original application, June. '1, 1943,". Serial No.

489,910, new Patent No. 2,126,032; datedAugust ,19, 1947: Divided and this applicatio ijhlne 9,

1947,- Serial No.*-'75 3;537 5 Y M This: application is a: divisionof? the subject matter shcwnin my. pending application, Serial.

No. 489,910; filed June=7,- 1943, now. Patent No.

2;426,032.-dated August;- 19, 1947, being directed tosubject matter shown and: described :but: not 1.

claimed in.said.application.-.

Thev ObjGGtfOf. the. invention. claimed in this divisional .applicationis. to provide: in. a trussed track construction. of the.type described inisaid application, aynovel sprocket and'iroller; com 1 bination .in which .thetrelative (sizes :and -position ing of the track driving sprockets and the 'track supporting-or idler. rollers is such that-onearoller contacts both theupper and lower track.railsurfaces; adjacent the corresponding sprocket; also to I provide a: structure: in which: thes sizeof the: sprocket=relative=to the pitch-length of the links is such that the horizontal distance between the axis ofeach roller and thatof 'theadjacent sprocket will be equalto the length of I a: linkwithout. the periphery I of the rol1er intersecting; the: axis of-- the sprocket, thusplacing the linksin positionior the rollers to pass overthem without knocking.

These: objects are accomplished by means of such structure andrelative arrangement of parts as will fully appearby'a perusal ofthe following specification andclaims.

In the drawings:

Figure 1 is.a side: elevation of: one form of my improvedendless track unit.

Figure-2 is an enlarged fragmentary elevation; partly in section; of'the-track" linkage detached.

Figure 3 is a plan-view*of a pair, of connected links.

Figure-sis a fragmentarytransverse section on the line 44 of Fig. 1.

Figure 5 is a fragmentary side elevation of a modified form of track unit.

Referring now more particularly to the characters of reference on the drawings, and particularly at present to Figs. 1 to 4, the track links, which are the essential features of the invention, each comprise a shoe 1 having a transverse cleat 2 on one end. A central pin boss 3 is formed with and inwardly from the shoe at said one end, and transversely spaced bosses, 4 are disposed in a similar position on the opposite end of the shoe to receive the boss 3 of an adjacent link therebetween. Link pins 5 swivelly connect corresponding bosses.

Longitudinally extending webbing 6, disposed in a plane at right angles to the shoe, extends between and connects the bosses inwardly thereof. The webbing at the boss 3 is in the form of symmetrically positioned relative thereto.

con c- (01. 305-8.)

a; central web element. 1, while at'the opposite end' it iszin. thetform. of'transversely spaced or forked elements. 8s: The webbing. terminates in aflat-longitudinal surface 9 which forms a roller engaging; rail. parallel to the shoe, andthe major portion of which; is the same width as the boss 3. Over said. boss, however, the surface'is in the form of. a. central tongue Hl' narrower'than'said boss; said tongue terminating. in abrupt shoulders ll at thejunctionwith. the widerportion of the surface. Beyondthe: shoulders saidsurface 9 is. forked to provideia slot l2= therebetween to receive thetongue'ofian adjacent link; the width of -this slot'being the-same. as. the spacing between theweb elementsB. A transverse pin 13' is securedin the web element. 7 adjacent the outerxend' of the tongue and projects laterally beyond opposite sides thereof; while a similarly disposed pin. I4 is secured in the web elements-ii and extends'a'cross the slot l2. Both pins lie in a plane parallel't'o the link pinrcenters inwardly thereof but outwardly of the -rail 9, as clearlyshown -in Fig. 2, and are considerably farther apart-than:the-bosses-and link-pins, but The bosses liin-which the pins l3 and i l-are mounted are the same width as the corresponding portions of the track- 9 and merge'intothe same witha;

curve; as shown. Formed along-the outer edge of -thewebbing 6- under the track and between the bosses 3 and 4 aresaddles lfiand [1 to receive the pins l3 and M, respectively, of adjacent-links, and facing the shoe. These saddles arepositioned; td seat'thepins' when the links are in straight'alinement with each other, the open end of-the-saddles-fiaring; as atl8, so-as toguide the pin's into seating position, if necessary; irrespec tive of any wear and consequent relative looseness at the link pins 5. v

The above pin and saddle arrangement requires that each pin and the saddle adjacent thereto shall be on the same circle whose center is the center of the adjacent link pin boss, as clearly shown in Figs. 1 and 2.

The supporting structure about which the endless track linkage extends comprises pairs of sprocket wheels l9 spaced to engage the bosses 4. Each wheel has an uneven number of teeth 28, forming boss-engaging sockets therebetween and spaced one-half the distance between adjacent link pins 5. This arrangement provides for successive alternate engagement of the teeth with the bosses so that the wear will be distributed gradually over all the teeth and longer life is assured. The sprocket wheels are mounted in suitable longitudinal frames 2| disposed between the pairs of wheels, and track engaging rollers 22 are turnably mounted between the frames adjacent each pair of sprocket wheels on centers spaced from the wheel centers a distance equal to the length of a link between its pin centers. These rollers assure of straight line movement of the linkage between the end sprockets, or so that the link pins lie in a line projected between and tangent to the pitch diameter of the sprocket wheels.

It is to be noted that the diameter of the '1 and between the sprockets and comprising a pluralityof links of equal length with pivot pins 1 connecting the links at adjacent ends; and idler sprocket wheels and the number of teeth thereon are in such proportion to the pitch length of the links and to the size of rollers 22 that sprockets; of fifteen teeth (one-half of which are effective at any one time) will cooperate with linkage of a corresponding pitch length to enable a single roller 22 to contact both track surfaces of upper and lower links of the endless track.

' It will also be noted that in Fig. 1 I have shown an odd number of links in the endless track, together with sprockets having an odd number, of teeth, in order to show the relative positions of the links in the various positions theywould successively occupy when in motion.

In the structure shown in Fig. 5, the general arrangement and construction of the links, and the locking or trussing action, is the same as above described. However, the sprocket wheels 19a, instead of engaging the pin bosses 4a-of the links L, here engage pins 23 projecting laterally from the link webbing 6a centrally between the end bosses and inwardly thereof. 'Thisarrangement permits of a much smaller sprocket wheel than is otherwise the case. In order to prevent possible rocking of the links about the pins 23, when fully engaged with and passing about the sprocket wheels, the shoulders I la of the tracks 9a form stops then engaging the relatively narrow portions of adjacent links, as'shown.

From the foregoing description it will be readily seen that I have-produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets'forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a' departure from the spirit of the invention, as defined by the appended claims.

I claim: j

1. An endless track structure including end sprockets, an endless track unit extending about and between the sprockets and comprising a plurality of links of equal length and pivot pins connecting the links at adjacent ends; and idler rollers mounted on the structure and simultaneously engaging the inner faces of the links of both the. upper and lower runs of the unit; the l,size ofth'e sprockets relative to the pitch length of a link" being sjuch that the horizontal distance -betwenthe axis of each roller and that of the adja'cent sprocket will be equal to the length of a 1ink, without the periphery of the roller intersecting the axis of the sprocket.

3; An endless-track structure including end sprockets, an endless track unit extendin about and between the sprockets and comprising a plurality of links of equal length and pivot pins.

connectingthe links at adjacent ends; and idler rollers adjacent the sprockets mounted on the structure and simultaneouslyengaging the links of both runsof the unit when said both runs are tangent to the sprockets; the horizontal .distance between the axis of each roller and that of the adjacent sprocket being equal to the length of a link. I Y

4; In the combination of an endless trussedtrack structure having end sprockets and an endless track passing thereabout and comprising links REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number I 7 Name Date 1,271,239 ,Sullivan July 2, 1918 1,660,104 Smyth Feb. 21, 1928 1,872,129 Eilersgaard Aug. 16, 1932 2,364,857

Law Dec. 12, 1944 

